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प्रश्न
1 g of copper powder was taken in a China dish and heated. What change takes place on heating? When hydrogen gas is passed over this heated substance, a visible change is seen in it. Give the chemical equations of reactions, the name and the color of the products formed in each case.
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उत्तर
When copper powder in a china dish is heated in air, copper undergoes surface oxidation by reacting with the oxygen present in the air to form a copper oxide and forms a black layer on top.
\[\ce{2Cu(s) + O2(g)->[Heat]\underset{\text{Black colour}}{2CuO(s)}}\]
When hydrogen gas is passed over the hot copper oxide, it reacts with hydrogen gas to form elemental copper and water will be produced in the liquid state.
\[\ce{CuO(s) + H2(g)->Cu(s) + H2O(l)}\]
संबंधित प्रश्न
When hydrogen is passed over copper oxide, copper and steam are formed. Write a balanced equation for this reaction and state which of the chemicals are reactants.
With the help of an appropriate example, justify that some of the chemical reactions are determined by Change in temperature.
Give chemical equation for the reaction involved in the above case.
Zinc oxide reacts with carbon, on heating, to form zinc metal and carbon monoxide. Write a balanced chemical equation for this reaction. Name (i) oxidising agent, (ii) reducing agent, in this reaction.
Write balanced chemical equation with state symbols for the following reaction:
Barium chloride solution reacts with sodium sulphate solution to give insoluble barium sulphate and a solution of sodium chloride.
Balance the following chemical equation :
Na2CO3 + HCl → NaCI + H2O + CO2
Write the balanced chemical equation of the following reaction.
potassium bicarbonate + sulphuric acid → potassium sulphate + carbon dioxide + water
\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]
State what is a ‘balanced equation’.
Write a balanced equation for the following word equation:
Potassium bicarbonate → Potassium carbonate + Water + Carbon dioxide
Writing a chemical reaction in brief by using chemical formulae is called as _______.
A student took a small amount of copper oxide in a conical flask and added dilute hydrochloric acid to it with constant stirring. He observed a change in colour of the solution.
- Write the name of the compound formed and its colour.
- Write a balanced chemical equation for the reaction involved.
